I'm releatively new to mold making/casting and I accidentally ordered Mold Max 20 instead of the Mold Max 30 I'm accustomed to. I'm concerned a softer 20A mold will cause warping with some of the flatter parts when pressure casting and/or less durability of the mold over time. I've noticed many prefer the 30A hardness for similar applications and I was wondering if Mold Max 20 is too soft, and if not, are there any additional factors to consider when using it versus the 30A? In short, can I forge ahead with Mold Max 20 worry free, or should I return it for the 30A to be on the safe side?

(The application in question is for relatively small 1/56 scale parts that will be pressure casted using Smooth-Cast 10. Both the molds and castings will cure at approximately 40-45 psig, and the average mold size will be roughly 3"x 6". The largest flat pieces to mold are approximately 2" x 3" and 3mm-5mm thick.)

Thanks again for your time, and any help would be greatly appreciated!